All in all, the sort of stuff rivalries and high-drama playoff chases are made of.

Except, in this particular case, Evan Gattis’ two-run single in the fifth, and the six innings thrown by Teheran (9-5) while allowing one run, combined to produce Atlanta’s season-high 12th consecutive win, padding their NL East lead to 14 1/2 games over Washington.

It was the latest weak hitting performance by a Nationals club that’s had trouble at the plate since April and is now five games under .500 a year after leading the majors with 98 wins.

Gattis’ big hit came off Gio Gonzalez (7-5), who pitched one night after Major League Baseball announced its Biogenesis investigation cleared the left-hander.

Adding to the theatrics: Gattis was only in the game because he replaced Jason Heyward, who left with a neck muscle strain after popping out in the first inning.

Harper put Washington ahead 1-0 with one out in the third, driving the first pitch of the at-bat onto the grassy hill in straightaway center for his 17th homer.

Harper paused a bit as he left the batter’s box, watching the ball fly, then dropped his bat and took a slower-than-usual-for-him trot around the bases.

Asked about Teheran’s intent during Harper’s next turn up, in the fifth, McCann answered: “I’m not sure. I don’t have the ball.”

When Harper went to the plate with Washington trailing 2-1, Teheran’s first pitch hit him on the right leg. Harper barked at Teheran and pointed at the right-hander. McCann moved toward Harper, before an umpire got in the way.

Members of both teams streamed onto the field, but they stayed separated and no punches were thrown. Even Heyward came out onto the grass, with a blue shirt on but not his jersey.

Not long after, the clubs’ official Twitter feeds mixed it up a bit.

The Braves tweeted: “Clown move bro,” tweaking Harper’s famous retort to a reporter last season, “That’s a clown question, bro.”

The Nationals then replied on Twitter: “Which part, giving up the home run, or drilling the 20-year-old on the first pitch his next time up?”

Teheran wound up allowing four hits and the lone run. He gave way to Avilan, who got out of that jam in the seventh. Jordan Walden struck out the side in the eighth, and Craig Kimbrel did the same in the ninth, collecting his 35th save by whiffing Harper swinging at a high, 99 mph fastball.

Asked afterward whether he thought about charging the mound when he got hit, Harper said: “Nah, I wasn’t going to go out there. I mean, 14 1/2 games down, and I need to be in the lineup.”

Notes: The Braves listed Heyward as day to day. After the game, he said a doctor told him it was a spasm. … Former major league closer Billy Wagner, who spent the final season of his 16-year career with the Braves, was in the visitors’ clubhouse before the game. Wagner, now a high school baseball coach, recently wrote an autobiography called “A Way Out.” “It’s not meant to be a best seller,” Wagner said. “It’s meant to help that kid that is in Southwest Virginia, who somebody said, `You’re not going to be anything, and you’re never going to accomplish anything.’ It’s meant for those people, so that they can read it and go, `Well, this kid was in the same situation.’ You might not go on to be a major leaguer, but there’s a way out.”